The National Alzheimer's Coordinating Center (NACC) (http://www.alz.washington.edu) was begun in 1999 to facilitate collaborative research among the Alzheimer's Disease Centers funded independently by NIA as the Alzheimer's Disease Centers Program since 1984. During the initial phase of its development, NACC collected a minimal data set (MDS) of clinical data on the subjects who had been enrolled at ADCs since 1984. Then in 2005, through close collaboration with NIA and the ADC Clinical Task Force, a detailed clinical evaluation and data-collection system was implemented called the Uniform Data Set (UDS); its protocol required annual follow-up examinations to monitor change over time in the patients and normal controls. About 66,000 persons were included in the MDS and 29,000 so far in the UDS (some with up to seven annual follow-up visits). From the MDS and UDS there is a total of about 13,000 persons who have died and had an autopsy to determine pathologic basis for their condition. All of these data have been collected by NACC and are housed in the NACC database. The data are freely available to researchers on request. There have been 306 publications within the 2009 - 14 grant cycle. NACC develops the clinical forms and documentation for all the data collection, working closely with the ADC CTF and with each Center. We have become an integral part of the ADC Program, not only to collect enrollment data and monitor ADC progress, but also to provide a large and unparalleled research database to the scientific community. We are now applying to continue NACC's efforts for another five years. During that time we will: a.) Maintain and increase the research capability of the NACC database by adding refined diagnostic data and, as it is approved by the CTF and NIA, disease specific modules as well as imaging and other biomarker data. We have maintained high data quality standards over the years and will continue to do so, through a detailed system of database error checks and communication with the Centers. b.) Facilitate and conduct research using NACC data by providing data and consultation to investigators; providing competitive peer-reviewed funding to several projects per year; and conducting internal applied and theoretical research. c.) Collaborate with national and international efforts on AD and other dementias, such as the Alzheimer's Disease Genetics Consortium, and make the UDS and other instruments available to non-ADC researchers anywhere in the world. d.) Continue the NIA-required administrative coordination of ADC meetings and ADC communications.